2001/05/02 by Brad M. S. Hansen · 43 citations
Medicine · Physics and Astronomy · Psychology · #Astronomy #Astrophysics #Biology #Galactic halo #Galaxy #Gamma-ray bursts and supernovae #Genetics #Halo #Massive compact halo object #Medicine #Milky Way #Physics #Population #Proper motion #Psychology #Pulsars and Gravitational Waves Research #Sanity #Stars #Stellar, planetary, and galactic studies #White (mutation) #White dwarf #astro-ph
paper · pdf · doi:10.1086/323495
published in The Astrophysical Journal 558(1), L39-L42 (IOP Publishing) · TeX, Submitted to Astrophysical Journal Letters
arxiv created 2001/05/02 · openalex publication_date 2001/09/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The recent discovery of a population of high proper-motion white dwarfs by Oppenheimer and coworkers has caused a lot of speculation as to the origin of these stars. I show that the age distribution of the white dwarfs offers a kind of sanity check in these discussions. In particular, the majority of the identified population appears to have a similar age distribution to those in the standard, thin-disk white dwarf population. This is not what is expected for either the halo or thick disk, which are thought to be old populations. A subset of the Oppenheimer "halo" sample does indeed possess an age distribution consistent with a halo origin, but the density is smaller and consistent with the results of Gould, Flynn, & Bahcall for a high-end mass function slope of -0.9.